Method and apparatus for twisting wires



Oct. 6, 1964 s. N. SCHLEIN METHOD AND APPARATUS FOR TWISTING WIRES FiledSept. 20, 1961 4 Sheets-Sheet 1 m W wm w A mi u 5 S. N. SCHLEIN Oct. 6,1964 METHOD AND APPARATUS FOR TWISTING WIRES Filed Sept. 20, 1961 4Sheets-Sheet 2 W////////////////////////// R\\\\\ \m;

INVENTOR Fl'y-JE Seymour/l ch/21' 1 BY d. flu ATTORNEY 1964 v s. N.SCHLEIN 3,151,437

METHOD AND APPARATUS FOR TWISTING WIRES Filed Sept. 20, 1961 4Sheets-Sheet 3 INVENTOR 5e Ymoaf 4 Sc file n F' .dE BY 19. My

# ATTORNEY Oct. 6, 1964 s. N. SCHLEIN METHOD AND APPARATUS FOR'IVWISTING WIRES Filed Sept. 20, 1961 4 Sheets-Sh eet 4 INVENTORSeymour- /Y h M ATTORNEY United States Patent Island Filed Sept. 20,1961, Ser. No. 139,528 13 Claims. (Cl. 57--25) The present inventionrelates to a machine for twisting a group of wires in a zone ofpredetermined length substantially midway between its ends. It isparticularly useful in conjunction with the preforming of a hard twistedportion on a half lay of preformed helical anchor rods.

In providing anchoring means for electrical conductors, it hasheretofore been the practice to preform various lengths of round, hardresilient wires into open helices of a predetermined internal diameter.These helical wires are then assembled into groups to provide half lays.The groups maybe cemented together to provide a unitary half layassembly. The half lay thus provided was then twisted by hand in a zoneof predetermined length, usually midway between its ends to provide afull lay central zone which was of smaller diameter and having half layend portions of the original open helix conformation. The structure thusprovided may be utilized for various purposes. For instance, the hardtwisted portion is bent to form a loop or bight which is secured to asuitable support, such as a pole or to an insulator on the pole.

The two half lay portions, which are arranged so that the open helicesdefined thereby are 180 out of phase with each other, are applied to aline or cable by first wrapping one leg of the dead end around the cableand then wrapping the other leg in position in the spaces left betweenthe helices of the other leg.

The twisting of a half lay by hand is not only timeconsuming but islaborious and this is particularly true when relatively thick helicalwires are used to form the half lay. Although a half lay is described,less or more than a half lay can be so twisted if desirable. Such anelement, after being twisted, is illustrated in FIGS. 2, 3, and 4. Asshown in FIG. 2, the open helical conformation at the ends is shown at Aand the hard twisted center portion is shown at B. In actual practice,the parts A would be considerably longer than illustrated. The interiorA of the part A has an internal diameter slightly less than that of theconductor or cable to which it is to be applied. The pitch of theindividual elements may be the same as, slightly less than, or evenlonger than the pitch of the wires of the cable.

In accordance with the present invention, a machine is provided by meansof which a half lay may be quickly twisted in a zone of a predeterminedlength substantially midway between its ends.

The invention will be better understood by reference to the accompanyingdrawings in which:

FIG. 1 is a side elevational view of a portion of my improved machine,with part of the machine broken away;

FIG. Zis an enlarged fragmentary elevational view of a twisted half layas formed on the machine of the invention;

FIGS. 3 and 4 are sectional views taken from a plane from the lines 3-3and 4-4, respectively, of FIG. 2;

FIGS. 5, 6, and 7 are cross sectional views taken from planes passingthrough the lines 55, 6-6 and 77, respectively, of FIG. 1, with themovable jaw of each clamp in open position;

FIG. 8 is a view of the clamping means shown in FIG. 7, with the movablejaw of the clamp in closed position;

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FIG. 10 is an enlarged cross sectional view taken from I a plane passingthrough the line 1ll-1ii of FIG. 7;

FIG. 11 is a cross sectional view taken from a plane passing through theline 11-11 of FIG. 1, looking in the direction of the arrows, with themovable jaw of the clamping means in open position;

FIG. 12 is an enlarged detail view of the movable clamping jaw shown inFIG. 13, with the movable jaw in closed position;

FIG. 13 is a view taken from a plane from the line 13-43 of FIG. 12;

FIG. 14 is an enlarged fragmentary elevational view of the right end ofthe machine of FIG. 1;

FIG. 15 is a detail plan view as seen from a plane in dicated by theline 1515 of FIG. 14 of the switches and cams for'controlling theoperation;

FIG. 16 is a cross sectional view taken from a plane indicated by theline 1616 of FIG. 14;

FIG. 17 is a cross sectional view taken on a plane indicated by the line17--17 of FIG. 14;

FIG. 18 is a side elevational view of a cam plate on a reduced scale;

FIG. 19 is a view, on an enlarged scale, of a switch and its operatingcam; and

FIG. 20 is a wiring diagram of one type of circuit which may be used inconnection with the machine to provide a certain form of operation.

Briefly, the invention contemplates a means whereby a preformed half laymay be laid in the machine and whereby the half lay is gripped at spacedapart positions in its mid-section and whereby the half lay is held atone of the positions and rotated at the other of the positions,resulting in the zone between the two positions being formed into a hardtwist that provides a full lay. During the twisting, tension is exertedon the half lay which prevents the twisted portion from buckling. Afterbeing twisted, the machine is reversed automatically. During thereversal, the half lay is held for a predetermined number of revolutionsbefore being released to prevent the half lay from whipping as it wouldif released immediately after twisting, due to the fact that the wire ishighly resilient and must be slightly over twisted in the initial partof the operation to provide the final hard twist in the completedproduct.

Referring now to the drawings, throughout which like parts aredesignated by like reference characters, and more particularly to FIGS.1 and 14, there is shown a bed 1 supported by legs 1a and having asupporting base 1b at its upper end.

At the extreme right of the machine, as viewed in the figures, there isprovided a reversible motor 2 connected by a coupling 3 to atransmission 4, which comprises a reduction gearing. The output from thetransmission 4 includes a shaft 5 which is connected to a drive head 6.The drive head 6 has extending outwardly therefrom toward the center ofthe machine, a plurality of drive rods 7 which are spaced apart fromeach other. Near one end of the rods 7 they support a first clamp member8 and at the end they are connected to a second clamp member 9. Theclamp means 8 and 9 are substantially identical.

The end clamp means 9 is rotatably supported in a bracket 12 ofgenerally C-shaped form, securely fixed to the bed plate 1b by screws,not shown. The bracket is provided with rollers 14 secured on spindles15 by nuts 16, the rollers thus extending outboard on the side towardthe right or head end of the machine. Each of the clamp heads 8 and 9are substantially the same, having a circular outer periphery providedwith a throat opening 19. A sufiicien-t number of rollers 14 areprovided that the head may be smoothly rotated within the supportingrollers.

Each of the heads has a fixed jaw 21) supported at the base of thethroat in the, exact center of the head. Opposite to the throat the headis cut away at 21 to provide a space in which is supported the clampingmechanism. The clamping mechanism includes a clamp lever 22, which issupported on a pin 23 and extends through an opening in the narrow neck24, with a clamp jaw 25 extending into the throat 1b and opposite to thefixed jaw 21). The clamp lever is rocked about its pivot 23 by togglelinkage 2d, 27, one end of which is pivoted on pin 28 in a recess 29near the periphery of the head. The knuckle 3b is pivotally connected tothe piston rod 31 of an air cylinder 32, the end of the cylinder beingpivotally journalled on a pin 33 which bridges a pair of bosses 34formed by providing an aperture 35 through the periphery of thecylinder. Thus, all of the operating clamping apparatus is confinedsubstantially Within the confines of the sides of the head. As wasstated, the heads are substantially identical but, as will later appear,a slight difference is provided in the clamp members 25a on the head 9and 25 of the head 8.

To the left of the bracket 12 is the non-rotatable clamp means. Aspreviously stated, the rotatable clamp means clamps and rotates the halflay while the non-rotatable clamp means holds the half lay againstrotation and also exerts a tension on the half lay during rottion by therotatable clamp means so that the hard twisted portion of the half laydoes not buckle during the twisting operation. The non-rotatable clampmeans includes a carriage 40, supported for longitudinal movement on thebed plate 112, by rollers 41. Lateral movement of the carriage on thebed is prevented by rollers 42, which extend downward alongside theedges of the bed plate 1b on each side thereof.

The rear end of the carriage 41) is provided with an upstanding bracket43 to which the piston rod 44 of an air cylinder 45 is connected. Theend of the air cylinder is anchored by a pin 46 to a bracket 47supported by the bed plate 15. As will later more clearly appear, theair cylinder 45, being connected to the carriage 40, may reciprocate thecarriage longitudinally on the plate 1b toward and away from therotatable clamp head. Movement toward the clamp head is limited by anadjustable stop 48, which merely comprises a cap screw threaded throughthe upwardly extending arm 49 of a bracket 49a, which is adjustablysecured to the bed plate 1b by screws, not shown. The stop screw 48 maybe locked in position by the usual lock nut.

A pair of non-rotatable clamp members 50 are supported on top of thecarriage 41) in adjustably spaced relation to each other. Hereafter, inthe interest of brevity, these non-rotatable clamp members will bereferred to as holding clamp members. Each of the holding clamp memberscomprises a generally rectangular frame having a fixed jaw 51 which issupported coaxial with the jaws 20 of the rotatable clamp member. Aswith the rotatable clamp members, the holding clamp member is providedwith a clamp lever 52 connected to a toggle 43, 54, the end of which isanchored on a pin 55 in a recess in a lower right-hand corner of theframe, as viewed in FIG. 11. A piston rod 56 is connected to the knuckleof the toggle by a pin 57, the piston rod being operated by the aircylinder 58, which is pivotally anchored at 59 on a pair of bosses inthe upper left-hand corner of the frame.

A bracket 43, secured to the end of the carriage 43, carries a V-shapedtrough member 61 which provides a support for the half lay. This troughmay be provided with an adjustable stop 62 which is one means fordetermining the postion of the half lay relative to the rest of themachine and prior to the twisting operation. An index rod 65 extendsupwardly from the carriage 4t and is used for engagement with the halflay to properly index its position in the mechanism. An alternativemeans for determining the position of the rod in the machine comprises acup it! supported by spokes 71 extending from sleeves 72 which are heldin adjustable position on the rods 7 by set screws 73. The end of thehalf lay may be inserted into and bottom in the bottom of the cup. Thecup is thus disposed axially of the clamping members and may be adjustedlongitudinally to the proper position for locating the half lay.

As previously stated, the rotatable clamp members a are operated by theair cylinders 32. Air for the cylinders is supplied through a conduit30, from a source not shown, to a rotatable joint 81 which connects to aconduit 82 that extends through the hollow spindle or shaft 5 and isconnected by suitable connections 83, PEG. 5, to a solenoid valve 84,which is mounted on the head 6. The valve is of the solenoid type andmay be one operated by single electrical impulses to supply airalternately to the lines 85, 36. Various types of valves may be used,and one which is satisfactory and well known is called the BellowsBulletin 300, manufactured by The Bellows Company, of Akron, Ohio. Thelines 85 and 86 are preferably of flexible tubing and may be releasablyclamped by a ring 8'7 to one of the drive rods '7. Adjacent the heads 8and 9 T connectors $8 and 89 are provided having branched lines 93 and91 extending therefrom, which connect to opposite ends of the cylinders32. It will thus be seen that the solenoid and the air lines rotatetogether with the drive head 6, drive rods 7 and the heads 8 and 9.

Current for operating the solenoids is supplied through the cable to abrush assembly 101, the brushes of which engage with contact or sliprings 2 carried on an insulated bushing 133 disposed about the hollowshaft 5. The rings 162 are connected by wires 152 and 184 to thesolenoid valve 84. The connection is such that when the solenoid valveis operated in one direction, the piston rod 31 of the cylinder isretracted to operate the levers 22 to open position and, when operatedin the other direction, the piston rod is extended to move the levers 22to a closed position. The two positions are shown in FIGS. 7 and 8.

Air is also supplied through a line 30 and a branch line 111) to apressure reducing valve 111 which supplies air to a first solenoid 112which is in series with a second solenoid 112a connected to operate theair cylinder 45. The solenoid 112 is operated by current through thewire 152 simultaneously with the other valves. The second solenoid valve112a is operated through the line 161 and through a branch line 152acontrolled by a relay 152b of the delay type. A branch air line 115 fromthe main air line 30 connects to a solenoid 116 which is energizedsimultaneously with the solenoids 112 and 84, and which admits air tothe lines 119 and 120 which are likewise connected to the cylinders 58with a similar T coupling to that of the heads, to operate the cylinders58 on the fixed jaw members.

As previously stated, the rotatable clamp members are arranged to clampthe half lay element securely to rotate and twist it. Each of the leverarms 22 is provided with a jaw 25 and 25a having welded thereto apressure foot at least one of which is shaped to conform to the innersurface of the half lay. The jaws 25, 25a are adjustably held to thelever arms 22 by cap screws 22a. Preferably the gripping member 25 is inthe form of a short cylindrical member having rounded ends the diameterof which is substantially the same as the inner diameter of the interiorof the open helix A. Since the head 3 may be adjustably positionedrelative to the head 9, the adjustment is such that the jaw on head 8engages the bottom interior of the half lay at A and the jaw on theclamp 9 engages crosswise of the half lay at A". The half lay is thussecurely gripped by the grippers, which first force the halp lay down,firmly into the sockets 20a of the fixed jaw members. The sockets Zdaprovide a semi-circular seat which conforms substantially to the outersurface of the half lay A, therefore, the half lay is gripped securelyat these two points without deformation.

The two fixed jaw gripping members 50 may be arranged to grip the halflay in a similar manner. The jaws 52!: are arranged in a similar mannerwith the jaw next to the twisting zone crosswise to the half lay and theother jaw seated in the interior. Like the heads 8 and 9, the heads 50may be adjustably spaced so that the interior of the half lay is engagedat C" and crosswise at C, to the left of the zone B, and immediatelyadjacent where the half lay is to be twisted. The gripping elementswhich extend crosswise of the half lay, may be made of a material whichdoes not mar the rods, such as nylon. The ones that seat in theinteriors are preferably of a hard material.

The operator takes a half lay of preformed elements and inserts itthrough the throat of the fixed and rotatable jaws, laying the same inthe fixed jaws 20 and 51. The end of the half lay may engage and bottomin the cup 70 or alternately the other end engage against the adjustablestop 62 in the trough 61. Only one of these elements are used at onetime and the one used is adjusted so that the heads, both the fixed androtatable, are disposed immediately adjacent to where the twisted zone Bis to be made, at opposite ends of the zone.

Proper circular orientation of the half lay is provided so that theclamps will properly engage therewith. The operator pulls the half layinto engagement with the rod 65, which engages with the transverseextremities of the interior convolutions of the half lay.

The half lay is then gripped by the fixed jaws and rotated by therotatable jaws upon energization of the motor 2. Adjustable timingmeans, later described, is provided whereby the motor can be made torotate a desired number of revolutions, or fractions thereof, in onedirection to twist the half lay, then stop and revolve in the reversedirection, back to the place where it started;

The performance of the twisting or untwisting operation, once themachine is started into a cycle, is all automatic. The number ofrevolutions of the head and the control of the air solenoids are allcoordinated to provide the desired results. It will be appreciated,however, that other types of controls than those illustrated can bedesigned to perform the same function and work equally well with themachine. One particular apparatus contemplates having a gear 120 on thespindle 5 in mesh with a smaller gear 121, which is mounted on a leadscrew 122 journalled in pillow blocks 123. The pillow blocks are in turnmounted on a sub-base 124 above the main base 112. The lead screw has anut 126 journalled thereon and carries a plate 127. The plate isprovided with longitudinally extending slots 128 in which are adjustablymounted switcfi operating cams 129. The bottom edge of the plate 127rides in a guideway 13%. It may thus be reciprocated in a longitudinaldirection alongside the lead screw 122 to move all of the camssimultaneously.

Opposite to the plate 127, at the edge of the base 124, a switch supportplate 131 is secured to an angle member 132 and carries in alignedspaced relation thereto a plurality of switches such as 134a, 134b and1340. Since the lead screw is driven through the reduction gearing bythe motor, the nut 126 travels in timed relation thereto and the camcarrying plate is carried past the switches to actuate them in theproper order. The' switches each have an operating lever 140 whichoperates an actuating pin 141. Preferably the switches are of the typewhich only operate upon movement of the cam past them in one direction.The end ofeach switch lever is provided with a pawl 142 having an arm143 in spring pressed engagement with the underside of the lever 140,the construction being such that the pawl 142 is pivoted when the cam129 passes in one direction, as best shown in FIG. 19, but when engagedby the pawl in the other direction causes the switch to operate. Thusthe cams may be arranged to operate the switches in only one direction,which can be in either direction depending upon the way the switch ismounted.

The operation of the device will be explained in conjunction with acertain type of operation which enables improved results to be obtained.This operation may be varied in practice to suit the occasion. Thesimplified wiring diagram illustrated in FIG. 20 illustrates a form ofcontrol for operating upon one particular size and type of Wire. Itshould be appreciated that the manner of controlling the machine can beeffected in many ways. The sequence of the operation, which will lead toa better understanding of the diagram as well as the operation of themachine, involves the starting of the machine by actuating a starterbutton 150. The starter button controls two circuits.

The lines L1 and L2 are energized by direct current from a source notshown. The start switch 150 is mounted on the bed 1b opposite therotatable clamp jaws in position for convenient actuation by theoperator. When the button is pushed, a first movable contact 151 makes aconnection between the line L1 and a conductor 152. The line L2 may bepermanently grounded. The circuit is then through one of the slip rings102 via a winding 153 on solenoid valve 84 to ground. This causes bothof the cylinders 32 on the rotary heads to close the clamp jaws,securely gripping the half lay.

Simultaneously current is supplied to the Winding 154 of solenoid valves116 to cause the operation of the holding jaw cylinders 58 actuating theholding jaws to a closed position on the half lay.

At the same time, current is supplied to the winding 190 of a startersolenoid valve 112 which is disposed in series with the carriage controlvalve 112a, and through the closed contacts of the relay 152k and theline 152a to the lower winding 155a to operate the valve 112a to admitair to the rear of the cylinder and to cause the rod 44 to push thecarriage 40 toward and against the stop 48. The movement of the carriageto the right foilows the clamping of the half lay because the cylinder45 .is a larger cylinder and it takes more time for the pressure tobecome effective. The longitudinal movement of the carriage 40, in thisinstance, although slight, causes the half lay to be securely seated andsettled in the gripping aws.

Continued pressure on the start switch button causes the switch blade toclose the circuit to the line 161. This furnishes current through theline 163 to a relay coil 162, which is grounded to line 164 and causesthe armature 162a to operate the switch blades a to f inclusive. Theswitches a to e inclusive close and the switch 1 opens. Switches a andI; close a circuit between the lines L1 and L3 to the motor armature 2through the lines 169 and 170. Switches 0 and d close a circuit throughthe lines 167 and 168 to the field winding 166. Switch 6 closes andcompletes a circuit from line L1 through line and normally closed switch134a to coil 162 and thus provides a holding circuit which keeps therelay locked in when the switch 150 is released. At this time the motorstarts and rotates the heads 3 and 9 in a clockwise direction, as viewedfrom the right end of FIG. 1.

Should the half lay be the opposite hand of pitch to that shown in FIG.2, a polarity reversing switch in lines L1 and L2, not shown, wouldsimply be used to reverse the polarity of the lines L1 and L2 and thesame operation being described would be carried out, with the directionof operation of the motor reversed.

At the same time as the motor starts, a current is supplied to thewinding 155 of solenoid valve 112a, through the line 161 which reversesthe pressure in the cylinder 45, air being admitted at the opposite endto exert tension on the carriage 40 and on the half lay. The tension orpressure on the carriage is determined by the setting of the reducervalve 111 and is determined empirically. during operation and is ofsufiicient tension to prevent kinks or buckling of the wires in zone Band to assist in forming a hard twist during the twisting operation. Atthis time the relay'lSZb is also operated to open the line 152-1521: tothe coil 155a of the solenoid valve 112a.

When the motor starts, the timing shaft 122, which is driven by thegears 129421, also starts to rotate and the nut 126 with the plate 127and its operating cams 129 is slid along opposite to the switches 134a,1341? and 1340. The first movement of the cam plate causes an immediateclosure'of the switch 134b, which is a normally closed switch. Nothinghappens in this circuit, however, because the switch is open.

As previously stated, the. number of revolutions for twisting the halflay will vary, depending on the diameter of the half lay, the size ofthe wires and the length of the zone to be twisted. The wires normallybeing a hard resilient material, the material is preferably slightlyover twisted to make it take the desired set. When it is re leased, itwill untwist to some extent and remain in the desired state.

If the wires or rods were released immediately after being twisted,there would be a tendency for the rods to Whip and result in possibleinjury to the operator. Therefore, the motor is reversed a predeterminednumber of revolutions before the rods are released, to relieve thetorsional strains.

After the desired number of revolutions in a clockwise direction, themotor is stopped and reversed. This is brought about by one of the cams129 engaging the switch 134a to open the circuit. This deenergizes theholding coil 162 and the contacts a, b, c and d are opened deenergizingthe field 166. The contact closes at the same time.

Upon the closure of contact 1, a circuit is made to the holding coil 180through the lines 181 and 182 connectting through the closed switch 134bto line L1, which energizes the coil 180 and closes the switches g, k, mand n. The closure of these switches results in a reversal of current inthe motor which stops quickly and reverses, rotating in the counterclockwise direction and starting to untwist the half lay. At the sametime the motor stopped, the line 161 which connected to line 153, becamedeenergized, and the line 181a to the coil 19% of solenoid valve 112 wasenergized to shut off the air to cylinder 45.

The nut 126, with its cam plate, is now traveling in the other directionand after a predetermined number of revolutions of the head, one of thecams 129 engages with the actuator of switch 1340 to momentarily closethe switch which supplies a pulse of current from the line L1 throughthe conductor 184 and slip ring 102a by way of a conductor to the coil153a of the solenoid air valve 84. At the same time the other coils forvalve 154 are energized. This causes all the clamp means to open,releasing the half lay.

The reverse revolutions continue, the cam plate and its cams moving backtoward its original position. Eventually the switch 134]) is operated,which opens the circuit to the holding coil 186, and the motor stops.

The stopping occurs with the throats in the rotary gripping membersbeing aligned with the opening into the bracket 12, as shown in FIG. 17.The twisted half lay is then removed and replaced by another untwistedhalf lay and the process repeated.

A typical cycle of operation may involve five movements of the carriage49, all of which are desirable to produce a uniform product, although insome instances some of the movements may be omitted.

The rod is first clamped by the clamping means. This occurs very quicklyafter the solenoid is operated to admit air to the cylinders 32 and 53,because these cylinders are small. At the same time pressure is admittedto the rear of the cylinder which, because of its larger volume does notbecome effective as quick as the clamp cylinders. This causes a firstmovement of the carriage 40 to the right, pushing it tightly upagainstthe stop 48-49. This assists in seating the clamps securely onthe half lay. Almost immediately after this occurs the heads 8 and 9start to rotate. Immediately after the rotation starts, the valve 112ais operated in the opposite direction to admit air to the front end ofthe cylinder which starts pulling the carriage toward the left end ofthe. machine, this being a second movement of the carriage.

During the twisting operation, the. desired pressure is maintained inthe cylinder 45 to exercise the desired amount of tension on the wires.As the wires twist up, a third movement of'the carriage to the rightoccurs, which is a secondary movement due to the twisting of the wireswhich cause the twist zone to be shortened. At this time the carriage 40moves to the right against the pressure exerted by the cylinder 45. itshould be noted that the pressure in the. cylinder should-be such thatthis movement can occur since it aidsin enabling a hard, closely woundtwisted zone to be made without unduly stretching the wires.

When the rotary. heads reverse, there is a fourth movement of thecarriage to the left, due to the untwisting of the previously slightlyovertwisted zone. After the desired. amount of untwisting occurs, thepressure in the cylinder 45 is released and the fifth movement of thehead to .the right occurs since the release of tension on the twistedzones causes the wire to pull the head back toward its originalposition.

The machine is also useful in the manufacture of rods where the centerzone B is of larger diameter than the ends zones. Such rods are usefulin conjunction with the making of line splices where the smallerdiameter helices atone end are first wrapped around the line and thenthe enlarged part, over the splice and finally the remaining smallerdiameter helices wrapped around the line the other side of the splice.The parts are wrapped around the line usually have the same or shorterpitch and the same lay asthe line and are of slightly smaller diameterin order. that. they grip the line tightly. The part that bridges thesplice, which can be any of theconventional type of splice units, has-aconsiderably larger inside diameter to the helix than the end parts.

The manufactureof the above is carried out by placing the rods in themachine the same as described in the first operation. However, insteadof twisting the rods, they are now untwisted by rotating the head in theopposite direction to the direction of the lay. During the untwistingoperation pressure is applied to push the ends of the zone B toward eachother and thispressure causes the helix to beenlarged. As in thetwisting operation, the untwisting is continued until the enlargement isslightly larger thanthe finished produce in order that the ultimatepermanent set, when the rods are released, will be of the desiredamount.

When the machine is usedto cause an untwisting and enlargement of thehelices, the operation is substantially a reversal of the twistingoperation. In this instance, the wire are gripped at the ends of thezone to be untwisted. At this time the carriage 40, with its holdingheads 50, is spaced away from the stop 48-49. At the start of theoperation a slight pull is first applied to the wires which assist inseating the clamp on the wires. Then as the'r'otation of theheads startsin the opposite direction, air is admitted to the rear of the cylinder.The combination of endwise pressure on the wires and the untwistingaction of the rotary head causes the wires to bulge outwardly and assumea lesser pitch. The movement continues until the wire is untwistedslightly beyond the desired amount because, when it is released, it willcollapse to a certain extent. After a predetermined number ofrotations'of the head, it is then reversed and then the pressure isreleased after which the wire is released and the head continues itsrotation to the normal position.

It is apparent that the construction of the machine is such that variousmodifications of the controls may readily be made and thus the machineprogrammed to provide any desired form of operation.

The circuit shown and described merely shows one manner of its operationand has been simplified in order to more clearly show the versatility ofthe machine. For instance, it has been illustrated as using directcurrent throughout. In actual practice, the lines L1 and L2 would beused merely to supplydirect current to the motor and the varioussolenoids and relay coils would be operated by stepped down alternatingcurrent at a much lower voltage, such as 6 or 12 volts.

Likewise the cams 129 and switches 134a, 134b and 134s could be placedin different positions than that shown, and, the number of cams andswitches increased to provide the desired programming. For instance,limit switches would normally be provided at the extreme limits ofmovement of the cam plate 127, disposed in the motor circuit to cut ofithe motor in event of failure of the pro gramming switches to operate.

The drive of the rotary head through the torsion bars 7 provides severaladvantages. One of the advantages resides in the fact that they providea drive to the heads with a certain amount of resiliency which preventsextreme shocks to the head and the product.

It also permits quick and easy adjustment of the rotary heads relativeto each other and this enables the machine to operate upon a wide rangeof different pitch helices. This adjustment feature is also facilitatedby having the clamping mechanism disposed substantially within thelateral confines of the head so that they may be brought very closetogether when helices of short pitch are being twisted or untwisted.

The provision of two different gauges 70 and 62 for placement of thewires allows the most convenient one to be used.

Having thus described my invention in an embodiment thereof, I am awarethat numerous and extensive departures may be made therefrom withoutdeparting from the spirit of the invention as defined in the appendedclaims.

I claim:

1. A machine for twisting a partial lay of open helically preformedwires in a zone intermediate its ends into a hard twisted full lay, saidmeans comprising a first clamping means movable into firm clampingengagement with the wires of the partial lay at one position and asecond rotatable clamping means movable into firm clamping engagementwith said partial lay of wires at a spaced distance from the firstclamping means, means for rotating the second clamping means relative tothe first clamping means to twist that portion of the partial laybetween the two clamping means to provide a hard twist full lay.

2. A machine as described in claim 1, wherein means is provided formoving one of the clamping means, under tension, away from the other toapply tension to the portion of the wires being twisted.

3. A machine as described in claim 2, wherein said rotating means isreversible to rotate said clamping means in the opposite direction toremove the torsional strains in the twisted portion of the wires.

4. A machine for twisting a portion of a half lay of wires of openhelical formation into a hard twisted full lay comprising a first andsecond clamping means movable into firm clamping engagement with theinner and outer surfaces of said half lay at a spaced distance from eachother and the ends, and means for rotating one of said clamping meansrelative to the other to twist the zone of the half lay between theclamping means to a sufficient extent to produce a full lay zoneintermediate the half lay end portions.

5. A machine for twisting a portion of a half lay of preformed wires toopen helical formation into a hard twisted full lay zone intermediateits ends, said machine including means for holding the half lay againstrotation including a first clamping means arranged at a predetermineddistance from one end of the half lay and including a frame having aseat therein for receiving the outer surface of the half lay, a clampfor engaging the interior of the half lay, a second rotatable clampingmeans spaced from the first clamping means including a support having aseat therein for receiving the outer surface of the half lay, a clampfor engagement with the inner surface of the half lay, means forrotating the second clamping means relative to the first clamping meansincluding a driving shaft, a base connected to the driving shaft, and aplurality of spaced bars connected to said base and the second clampingmeans for rotating the second clamping means to twist the half laybetween the clamping means, means for applying tension to that portionof the half lay between the first and second clamping means while it isbeing twisted to prevent buckling and to enable the twisted portion ofthe half lay to be formed into a full lay having compact smoothconvolutions, said driving means being reversible to release the strainsin the twisted portion of the half lay, and means releasing said clampsto enable the half lay'having the twisted midportion to be released fromthe machine.

6. A machine for twisting a plurality of wires of preformed open helicalformation assembled into a group of less than a full lay into a hardtwisted full lay zone intermediate its ends including means for holdingsaid wires adjacent the zone to be twisted comprising a frame having aseat of engagement with the exterior of the wires and clamp meansmovable into the interior of the helices to press the wires against theseat, a second pair of rotatable clamp means each comprising a rotatableframe having a seat for engagement with the exterior of the wires andclamp means movable into the interior of the helices for pressing itinto clamping engagement with the seat, reversible means for rotatingthe rotatable clamp means to twist said wires into a zone between saidclamp means comprising a rotatable base member, torsion bars extendingfrom said base member and connected to said rotatable clamp means.

7. A machine for twisting or untwisting a plurality of wires ofpreformed open helical formation assembled into a group intermediate itsends including a pair of means for holding said wires adjacent the zoneto be twisted or untwisted, each comprising a frame having a seat forengagement with the exterior of the helices and clamp means movable intothe interior of the helices to press the wires against the seat, asecond pair of rotatable clamp means each comprising a rotatable framehaving a seat for engagement with the exterior of the helices and clampmeans movable into the interior of the helices for pressing it intoclamping engagement with the seat, reversible means for rotating therotatable clamp means to twist or untwist said wires in a zone betweensaid clamp means comprising a rotatable base member, torsion barsextending from said base member and connected to said rotatable clampmeans.

8. A machine as described in claim 7, wherein each of said pair of saidholding means is adjustable toward and away from each other to enablethe clamp means to engage with adjacent convolutions of said helices.

9. A machine for twisting a plurality of wires of preformed open helicalformation assembled into a group of less than a full lay in a zoneintermediate their ends into a hard twisted full lay comprising a firstclamping means and a second clamping means arranged to grip said wiresat the boundaries of the zone to be twisted, a bed, a carriagereciprocably mounted on the bed, pneumatic tension means connected tosaid carriage to move it in opposite directions, said first clampingmeans being mounted on the carriage and comprising first and secondclamp members one of which is adjustably mounted on the carriage foradjustment toward and away from the other, a support means mounted onsaid bed and said second clamping means comprising a pair-of clamp.meansone of which is rotatably mounted in said support .means, drivemeans for rotating said second clamping means comprising a motor, adrive plate rotatably connected tosaid motor, a plurality of torsionbars connected between said drive plate and one of said second clampmeans, the other of said second clamp means being adjustably mountedupon said torsion bars for adjustment toward and awayfrom'the other.

10. A machine for twisting a plurality of wires of preformed openhelical formation assembled into 'a group of less than a full lay in aZone intermediate their ends into a hard twistedfulllay comprising afirst clamping means and a-second clamping means arranged to grip saidwires atthe boundaries ofthe zone to be twisted, a bed, a carria'gereciprocably mounted on the bed, means for exerting resilient tensionconnected to said carriage to move .it in opposite directions, saidfirst clamping means being mounted'on the carriage and comprising firstand second clamp members one of which is adjustably mounted on thecarriage for adjustmenttoward and awayfrom the-other .to clamp saidWires in adjacent helices, 'a-supportmeans mounted on said bed and saidsecond clamping means comprising a pair of clamp means one of whichis'rotatably mounted in said support means, drive means for rotatingsaid second clamping means comprising a reversible motor, a drive platerotatably connected to said motor, a plurality of torsion bars connectedbetween said drive ,plate and one of said second clamp means, theotherof said second clamp meansbeing adjustably mounted upon saidtorsionbars for adjustment toward and away from the other to clamp said wiresin adjacent helices.

11. A machine as-described in claim 10, wherein control means :isprovided connected to said motor and to said clamping means andtension/means'to operate them in timed relation to each other.

12.,A device as described in claim '11, wherein index means is providedon said carriage for engagement with References Cited in the file ofthis patent UNITED STATES PATENTS 556,203 Ordway 'Mar. 10, 1896 605,930Stauffer June 21, 1898 939,308 Personett Nov. 9, 1909 2,414,136Bodendieck i] an. '14, 1947 3,028,720 Honk Apr. 10, 1962 3,025,656 CookMar. 20, 1962 3,049,858 Bonds Aug. '21, 1962 3,052,079 Henning 'Sept. 4,1962 3,052,081 'Wallshein Sept. 4, 1962

1. A MACHINE FOR TWISTING A PARTIAL LAY OF OPEN HELICALLY PREFORMEDWIRES IN A ZONE INTERMEDIATE ITS ENDS INTO A HARD TWISTED FULL LAY, SAIDMEANS COMPRISING A FIRST CLAMPING MEANS MOVABLE INTO FIRM CLAMPINGENGAGEMENT WITH THE WIRES OF THE PARTIAL LAY AT ONE POSITION AND ASECOND ROTATABLE CLAMPING MEANS MOVABLE INTO FIRM CLAMPING ENGAGEMENTWITH SAID PARTIAL LAY OF WIRES AT A SPACED DISTANCE FROM THE FIRSTCLAMPING MEANS, MEANS FOR ROTATING THE SECOND CLAMPING MEANS RELATIVE TOTHE FIRST CLAMPING MEANS TO TWIST THAT PORTION OF THE PARTIAL LAYBETWEEN THE TWO CLAMPING MEANS TO PROVIDE A HARD TWIST FULL LAY.